Precessing display pager

ABSTRACT

A hand held paper pager is disclosed in which a transmitted message is displayed in alpha/numeric form by a precessing display which moves the received message across the display in a continuous fashion so that the display need be only large enough to present a relatively small portion of the total message at any given time. In one embodiment a dot matrix LED display is used and is driven by a recirculating shift register memory to provide the precession of the message as a result of the recirculation. In another embodiment the pager may also include a message entry section in which the precessing display is used to present and edit the message prior to transmission either via an acoustic telephone link to a remote transmitter, or directly from a transmitter carried in the pager/encoder package.

FIELD OF THE INVENTION

This invention relates to paging systems and.Iadd., .Iaddend.moreparticularly.Iadd., .Iaddend.to a hand held pager which silently storesthe message transmitted to the recipient in such a manner that themessage can be read out at the convenience of the recipient by aprecessing display.

BACKGROUND OF THE INVENTION

It is common practice to provide pagers which emit an audible toneindicating that a particular recipient is to receive a message.Thereafter, the message is transmitted via voice communication to therecipient whether or not this recipient is ready to receive the message.As a result, the content of the message is sometimes lost when therecipient either cannot remember the content of the message or a penciland paper is not immediately available to transcribe the message. Thisis particularly severe when telephone numbers or addresses aretransmitted. The result is frustration of the recipient and thenecessity of communicating with the originator of the message to obtainits content. In one broad aspect.Iadd., .Iaddend.this inventionalleviates the inconvenience of the prior art paging systems byproviding storage and recall of the transmitted message through the useof a precessing display of a stored message (soft copy unit) in anunattended unit.

In another broad aspect of this invention.Iadd., .Iaddend.a portableencoder unit is coupled via a telephone link to a common carrier pagingtransmitter. The system is compatible with existing transmitters andpermits the encoding of messages anywhere that telephone service isavailable. It is a feature of the subject invention that the encodedmessage may be transmitted through the common carrier transmitter audiochannel as a substrate for voice communication without alteration ofexisting unattended transmitting equipment. In this regard, in oneembodiment.Iadd., .Iaddend.the encoder includes a message entry keyboardand means for converting the entered message into a series of audiotones for transmission on the audio channel after the transmitter hasautomatically sent a predetermined address code.[.,.]. responsive to thedialed telephone number. Thus.Iadd., .Iaddend.no additional messageencoding apparatus or tone generating equipment is necessary at thecommon carrier transmitter. In one embodiment.Iadd., .Iaddend.theencoding unit may include a precessing display for message editing andreview prior to transmission.[.,.]. or.Iadd., .Iaddend.alternatively,other types of editing displays may be used.

As illustrated in U.S. Pat. No. 3,846,783 issued to Aspell et al. onNov. 5, 1974, it is known to provide a pager with a hard copy printout.While the Aspell patent describes generally the use of light emittingdiodes or liquid crystals for displaying a message, the subjectinvention provides, in one embodiment, for a precessing display whichrolls by characters across a limited field. This type display permitsthe display of messages which have a greater length than the display byprecessing the message across the display.

In one embodiment.Iadd., .Iaddend.the pager utilizes a ROM-driven LEDdot matrix display fed by a recirculating shift register memory whichgenerates the precession as it recirculates. In another aspect of thesubject invention.Iadd., .Iaddend.the LED display enables thepresentation of the message in the dark a portion at a time. In thesubject soft copy pager, the message is stored in the pager's memory andmay be recalled at the convenience of the recipient by a precessingalpha/numeric display so that the information contained in the messagecan be made available at the convenience of the recipient. In a furtherembodiment.Iadd., .Iaddend.the soft copy pager is provided with encodingmeans so that a message can be composed on the soft copy unit prior toits transmittal to a high power transmitter for transmission to anotherpaging unit.

It is therefore an object of this invention to provide an improved handheld paging system in which a message transmitted to a recipient isstored at the pager for readout at the convenience of the recipient.

It is another object of this invention to provide a pager which isinexpensive, silent and displays a message in alpha/numeric form aportion at a time.

It is a further object of this invention to provide a method oftransmitting a message in which the message is stored at a remotelocation in a memory and in which the message is recalled by therecipient at his convenience through the use of a precessing display.

It is another object of this invention to provide a precessing displaypager in which the precession is generated by a recirculating shiftregister.

It is .[.a.]. still .Iadd.a .Iaddend.further object of this invention toprovide a soft copy pager which may be utilized both for the receipt ofa transmitted message and for the encoding of a message to betransmitted thereby combining in one unit the two functions.

It is .[.a.]. yet still .Iadd.a .Iaddend.further object of thisinvention to provide a paging system in which messages may be locallyencoded and transmitted on the audio channel of existing unattendedcommon carrier transmitting equipment.

These and other objects of this invention will be better understood inconnection with the following .[.desription.]. .Iadd.description.Iaddend.in view of the appended drawings in which:

FIG. 1 is a diagrammatic representation of a soft copy pager/messageencoder combination which utilizes a precessing display;

FIG. 2 is a block diagram of one embodiment of the pager/encoder of FIG.1; and

FIG. 3 is a more detailed block diagram of a portion of thepager/encoder of FIG. 2.

DETAILED DESCRIPTION

Referring to FIG. 1.Iadd., .Iaddend.a pager 700 is illustrated in whicha received message is reproduced in alpha/numeric form by a precessingdisplay 702. This pager also can be used for message encoding and has akeyboard 704 for this purpose. The pager has an internal memory intowhich a message may be written, either by receipt of a transmittedsignal or by local keyboard message entry. In the encoding mode.Iadd.,.Iaddend.the message is .[.enetered.]. .Iadd.entered .Iaddend.into theinternal memory and then transmitted by an acoustic link 706 to atransmitting station. In one embodiment, the encoded message isdisplayed on a .[.12.]. .Iadd.twelve .Iaddend.character precessing LEDdisplay which is utilized for message composition and for editing priorto message transmission. A sufficient number of keys are provided on theface of the message encoder/soft copy pager to permit correction and toinitiate readout of the encoded message from the internal memory of thepager. The encoded message is made available at link 706 which isacoustically coupled through telephone lines to a remote high powertransmitting station. Alternatively, the message encoder/soft copy pagermay be provided .Iadd.with .Iaddend.a transmitter such that the addressand message may be transmitted from this unit for a short distance toother pagers within the area. For this purpose, a collapsible antenna712 is provided.Iadd., .Iaddend.as illustrated.

In either the receiver or encode mode.Iadd., .Iaddend.the message in thememory is precessed across the display. By precessing is meant that themessage is made to travel across the display such that the portion ofthe message that has already been viewed disappears, while at the otherend of the display new portions of the message are generated. As will beappreciated, receipt of a message may be indicated by any convenientmessage indicator. Various indicator lights, generally indicated byreference characters 708, are available on the face of the unit toindicate the various modes of operation of the device such as anindication of Power-On and receipt of a message, that a compose cycle isselected, that a message is being transmitted.Iadd., .Iaddend.or that amessage is being held. The recipient displays the message by pressing anappropriate key on the keyboard. Should the recipient wish to stop themessage from precessing.Iadd., .Iaddend.a "freeze" switch 710 isprovided. In this embodiment.Iadd., .Iaddend.the receipt of a newmessage automatically clears the old message from the memory included inthe soft copy pager unit. In .[.anaother.]. .Iadd.another.Iaddend.embodiment.Iadd., .Iaddend.the messages can be made to "stack"into memory in the order in which they arrive.

In operation, a message for the soft copy pager is transmitted with, forinstance, a predetermined digital address. After decoding of theaddress, the FSK message code is decoded within the pager and stored inan internal memory. This memory is read out in a precessing fashion to acharacter decoding read only memory (ROM) which is .[.utilied.]..Iadd.utilized .Iaddend.in driving an electronic alpha/numeric display.

It will be appreciated that this pager serves the function of preservingthe message for recall at the convenience of the recipient while.Iadd.,.Iaddend.at the same time.Iadd., .Iaddend.providing that the message maybe stored silently and recalled silently thereby not disturbingindividuals in the vicinity of the pager.

Thus, in one unit.Iadd., .Iaddend.a message encoder and messagereceiving apparatus is combined. The significance of the combination isthat the same precessing internal memory and the same read only memorymay be utilized for message encoding and message decoding. Thus, in oneembodiment.Iadd., .Iaddend.pager 700 functions as a soft copy pager, amessage encoder, and a message transmitter. A block diagram of oneembodiment of the soft copy pager of FIG. 1 having these threecapabilities is illustrated in connection with FIG. 2 and is nowdescribed.

Referring to FIG. 2, a block diagram of one embodiment of the soft copydigital message communicator is illustrated as including a receiver 720connected to an antenna 722. The output of the receiver is connected toan FSK demodulator 724. The output of the FSK demodulator includesserial data which is coupled both to a clock extractor 726 and to aserial-to-parallel register 728. The output of the serial-to-parallelregister is the ASCII code of the incoming data. This is applied to asix pole, two-position switch 730 which.Iadd., .Iaddend.in the receivermode.Iadd., .Iaddend.couples the data to the recirculating shiftregister memory. In the second position.Iadd., .Iaddend.switch 730couples keyboard generated ASCII characters into the memory. In thisfigure.Iadd., .Iaddend.the recirculating shift register memory isindicated by reference character 732 and the keyboard by referencecharacter 734.

The output of the FSK demodulator 724 is also coupled to an address orI.D. code recognition circuit 736 which, upon decoding of the properASCII character sequence, couples a signal to a mode control circuit 738which forces the system into the receive mode by control of switch 730and control of a clock extractor 726 which inter alia provides timingfor the data transmission in the transmit mode. A signal is alsotransmitted over line 739 from the ID code recognition circuit to clearmemory 732 in response to a signal indicating a mode change from modecontrol circuit 738. The status of the system is indicated by statusindicators 741 which are driven by the mode control circuit.

In the receive mode, data from the serial-to-parallel register 728 istransmitted to recirculating shift register memory 732 which is undercontrol of memory control shift register 740. The purpose of the memorycontrol register is to ascertain the length of the message stored inmemory 732 and the beginning thereof. This permits the readout of themessage from memory 732 to the dot matrix character ROM 742 followingthe complete reception of the message. The dot matrix character ROM isread out to a row driver and multiplexer 744 and to a data refresh andkeyboard decoder timing circuit 746. The display refresh and keyboarddecoder timing unit 746 provides the appropriate timing signals for thecolumn driver herein indicated by the reference character 748 such thatthe columns are actuated in the proper sequence to display memorycontents. The display in one embodiment is a .[.12.]. .Iadd.twelve.Iaddend.character LED dot matrix display 750 such as MONSANTO MKA3. Theline between ROM 742 and display refresh and keyboard encoder 746illustrated by line 752 is a two-way line which controls the timing ofthe character readout from the dot matrix in terms of the row driver andsynchronizes this with the column driver activation and the multiplexingthereof.

It is an important feature of this portion of the soft copy unit thatthe message be stored in the memory for readout at the convenience ofthe recipient and also that the message be formed in such a way that itcan be precessed across the dot matrix display. Readout of the messageis accomplished by actuation of switch 754 which activates mode control738 to establish a signal on line 756 thereby to control shift registertiming and control unit 758 to activate the memory control register 740which.Iadd., .Iaddend.in turn.Iadd., .Iaddend.activates memory 732 toserially dump its contents through to the dot matrix character ROM 742in a recirculating manner thereby to cause the displayed characters toprecess. Auxiliary switch 760 is provided to freeze the precession bycontrolling the memory control register.

It will be appreciated that memory 732.Iadd., .Iaddend.in essence.Iadd.,.Iaddend.acts as a refresh buffer to restore the readout characters sothat they can be read out again during recirculation. Thus, memory 732in one sense is not a destructive memory and will destruct the datatherein only upon command stimulated by the receipt of a new message, orby clearing due to keyboard encoding.

What has been described so far is the decoding of a received message bythe subject soft copy unit. As mentioned hereinbefore.[.,.]. inconnection with FIG. 1.Iadd., .Iaddend.it is possible to use this sameunit for encoding the message and displaying the encoded message priorto transmission. In this sense.Iadd., .Iaddend.the display is utilizedin the formulation of the message and can be utilized in a manner sothat errors in the message may be corrected prior to transmission. Toaccomplish this.Iadd., .Iaddend.the message is encoded by actuation ofkeyboard 734 which.Iadd., .Iaddend.in turn.Iadd., .Iaddend.actuatesdisplay refresh and keyboard encoder timing 746 to generate a .[.6.]..Iadd.six .Iaddend.bit character code over line 762 which is coupled toswitch 730 to enter the characters into the recirculating memory. Thisline also initially carries a signal which activates the mode control738 to generate a signal coupled to switch 730 to switch from itsreceive mode to a message composition mode. Thereafter, the message isentered into the recirculating register from the keyboard and issimultaneously read out via the dot matrix character ROM to the displayas described hereinbefore.

It will be appreciated that the output of the memory 732 is coupled to aparallel-to-serial converter 770 which converts the ASC II codedcharacters into a serial transmission for actuating FSK modulator 772 tomodulate transmitter 774 to transmit the data. In the receive or encodemode, although data is continuously coupled from memory 732 toparallel-to-serial conversion unit 770.Iadd., .Iaddend.there are noclock pulses delivered to this unit so that no data is transmitted.When, however, the message to be transmitted has been successfullyencoded, a character of a special type is transmitted on line 762 to themode control unit 738, which forces the mode to the transmit mode. Thisdevelops a signal on lines 775 and 776 to actuate the transmitter and toactuate clock extractor 726 to produce clocking pulses on line 778thereby to clock the parallel data into the parallel conversion unit 770from whence it is coupled to the FSK modulator. It will be appreciatedthat the transmitter utilized may be internal to the soft copy unit ormay be remote therefrom for the transmission of both the address and themessage to another remote paging unit which may be either an identicalsoft copy unit such as described, or a hard copy unit in which digitaladdressing is utilized. The FSK output as illustrated by line 780 may becoupled to a suitable modem which transmits the address and message overstandard telephone circuits to a remote transmitter such that thesubject soft copy message communicator may be utilized solely as theencoder. Thus.Iadd., .Iaddend.encoders at different locations may beconnected via a telephone link to the same transmitter with appropriatecircuitry at the transmitting station to prevent overlap or to allowsequential access.

The precession of the display is accomplished, in one embodiment, asfollows. The first character which is entered into the recirculatingshift register memory from switch 730 causes a single one bit wide pulseto be clocked into the memory control register 740. This bit willsubsequently be referred to as the .Iadd.".Iaddend.pointer.Iadd.".Iaddend.bit. The purpose of the pointer bit is to indicate thebeginning of the message within the total length of the shift registermemory. Its secondary function is to indicate the beginning of thedisplay refresh cycle within the shift register memory when it is usedfor that purpose.

A second function of memory control register 740 is to provide a timingpulse to indicate the duration of the message stored in the memory. Thisis accomplished by clocking into memory control register 740 a logiclevel "1" bit each time a new character is clocked into therecirculating shift register memory 732. In this way.Iadd., .Iaddend.alogic level .Iadd.".Iaddend.1.Iadd." .Iaddend.pulse is formed in thememory control register which is coincident or synchronous with themessage character contents of the recirculating shift register memory.

It will be appreciated that a .[.6 .Iadd.six .Iaddend.bit ASCII codedmessage is serially clocked into the recirculating shift registermemory. The beginning of this message is indicated by the aforementionedpointer bit and its duration .[.in.]. .Iadd.is .Iaddend.indicated by thenumber of logic level .Iadd.".Iaddend.1.Iadd." .Iaddend.bits enteredinto the memory control register. This permits the recirculation of themessage in the shift register memory via a feedback circuit within theshift registers. For this purpose.Iadd., .Iaddend.shift registers.[.menufactured.]. .Iadd.manufactured .Iaddend.by National SemiconductorCo., model MM5056 may be utilized.

The clocking of the message so as to permit recirculation isaccomplished via the output terminals of the shift registers within thememory control register. Depending on which portion of the cycle is thenpresent, a certain number of clocking pulses are provided to therecirculating shift memory to .[.accomplsih.]. .Iadd.accomplish.Iaddend.the recirculation. The clocking for recirculation is many timesthat for readout so that reloading of the memory during recirculation isdone at a fast rate between two readout clock pulses. The pointer pulseand the length of message pulses are decoded such that fast timingpulses to the memory are only delivered for a length of time sufficientto recirculate the message. In order to stop the message at theappropriate point of its beginning, the pointer bits are recognized andthe quick recirculation is terminated.

In the receive mode.Iadd., .Iaddend.the precession takes placeautomatically because the pointer bit is automatically shifted via thetiming control circuit to the memory control register. .[.this.]..Iadd.This .Iaddend.is accomplished by a timer comprising a monostablemultivibrator within shift register and timing control circuit 758which, when it times out, produces a clock pulse which shifts thepointer bit in the memory control register by .[.1.]. .Iadd.one.Iaddend.bit. In so doing, one character from the portion of the memorydisplayed is dropped and one character from the portion of the memorynot displayed is added. The time constant of this monostablemultivibrator is made compatible with the precession rate desired. Itwill be appreciated .Iadd.that .Iaddend.by altering the timingcomponents of the multivibrator.Iadd., .Iaddend..[.that.]. theprocession rate can be easily varied. Moreover, the precession rate isnot controlled by any fixed counter or counting-type logic but rather issimply dependent upon the time out period of the multivibrator. Theautomatic time out feature is disabled during the encode mode by themode control circuit.

The output signals from the recirculating shift register memory areapplied as inputs to the dot matrix character ROM 742. The dot matrixcharacter ROM drives the row driver multiplexing circuit 744 and.Iadd.,.Iaddend.via the display refresh and keyboard encoder timing circuit746.Iadd., .Iaddend.drives the column driver and multiplex circuit 748such that characters are read out of the dot matrix ROM in five columnsper character. Because of the recirculation of the shift registermemory, the dot matrix character ROM is refreshed with the message suchthat, in one embodiment, the .[.12.]. .Iadd.twelve .Iaddend.most recentcharacters are decoded by the ROM and are displayed. A Fairchild MemoryModel No. 3257 is utilized as the dot matrix character ROM. It will beappreciated that row driver 744 includes switchable current sources forapplying a voltage to the appropriate rows of the LED dot matrix display750. The columns of these displays are actuated by the display refreshand keyboard encoder timing 746 which sequentially actuates the columnsto produce the characters. This completes the description of thegeneration of a precessing display when the paging unit is in thereceive mode.

In the encode mode, one of the functions of the pointer bit is to blankthe display so that as each character is entered via the keyboard.Iadd.,.Iaddend.it replaces a blank portion of the display with the appropriatecharacter. In normal operation, .[.te.]. .Iadd.the.Iaddend.recirculating shift register memory refreshes continually. Withthe advent of the pointer bit.Iadd., .Iaddend.the recirculating shiftregister cyclically reads out blank characters or spaces. Upon thedepression of a character key.Iadd., .Iaddend.this character is addedafter the pointer bit and the blank characters are shifted one positionto the right in the shift register such that one of the blank charactersis lost and one character is added. This is reflected in the nextcharacter refresh cycle and the key depressed is now present for visualverification. The character refresh is going on all the time and at avery rapid rate such that the columns of the matrix display are rapidlyand sequentially actuated via the clocking of the display.Iadd.,.Iaddend.which also reads out the dot matrix character ROM. It will beobvious that the refresh cycle must be sufficiently rapid to avoidflickering of the display. It is therefore important when entering acharacter into the recirculating shift register memory that this be doneat the appropriate time. In this case.Iadd., .Iaddend.the appropriatetime means at the end of a refresh cycle. It is therefore the functionof the pointer bit to insure that the character is entered into therecirculating shift register memory at this particular point and time.When a character key is depressed.Iadd., .Iaddend.the pointer bit isdelayed by one bit position within the memory control register. Thispermits the next character to be entered at the correct time in therefresh cycle. When the display is full (.[.12.]. .Iadd.twelve.Iaddend.characters displayed) the delay of the pointer bit by .[.1.]..Iadd.one .Iaddend.bit results in the display now presenting thecharacters following this pointer bit such that one character is deletedand one character is added.

By the shifting of the pointer bit, what is displayed therefore are.[.11.]. .Iadd.eleven .Iaddend.old characters and one new character withthe new character being the last one entered. This corresponds to amanual precession of the display such that the precession is controlledby the position of the pointer bit within the memory control register.What has been accomplished.Iadd., .Iaddend.therefore.Iadd., .Iaddend.isthat by the depression of keys in the keyboard.Iadd., .Iaddend.a messageis loaded into the recirculating shift register memory in timedrelationship to the refresh cycle which is established by a pointer bitoriginated by depression of a control key and the appropriate characterkey in the keyboard. Since the recirculating shift register memory iscontinually read out to the dot matrix character ROM, what is read outof the shift register memory is displayed. Thus.Iadd., .Iaddend.changesin data held by the memory are immediately displayed.

Editing of the encoded message is accomplished very simply by precessingthe display to the point where the inaccurate or error character is atthe right hand most portion of the display. This corresponds to thepointer bit location and merely entering the appropriate correction atthat time replaces the character in error with the corrected character..[.the.]. .Iadd.The .Iaddend.corrected character then appears at thatdisplay position corresponding to the key depressed.

Thus.Iadd., .Iaddend.a convenience feature of this particular pager isthat there is provided on the keyboard a key which, when activatedsimultaneously with the control key, causes the precessing circuit totime out such that the display .[.precessed.]. .Iadd.precesses.Iaddend.by one character at a time in a forward direction,corresponding to one depression of the key. This enables editing of themessage by .[.exactly.]. .Iadd.the exact .Iaddend.positioning of themessage within the display such that locating .[.of.]. the errorcharacter at the right most display .[.positon.]. .Iadd.position.Iaddend.is easily accomplished.

Another attractive feature of the subject pager is that by.Iadd.activating .Iaddend.a simple freeze switch .Iadd.to its ONposition, .Iaddend.the automatic precessing circuit is disabled therebyfreezing the message on the display in .[.the.]. .Iadd.its.Iaddend.position at the moment that the freeze switch is actuated.Precessing continues when the precessing circuit is again enabled by.[.throwing.]. .Iadd.changing .Iaddend.the freeze switch to its OFFposition. It will be appreciated that the freeze switch is in the freezeposition during message composition.

It will also be .[.appreicated.]. .Iadd.appreciated .Iaddend.that bytapping off .[.of.]. the lines between the recirculating shift registermemory and the dot matrix character ROM to parallel-to-serial conversionshift register 770, the encoded message may be made available at theoutput of this shift register for transmission.

In order to transmit the encoded message.Iadd., .Iaddend.a control keyis depressed on the keyboard along with a preselected character key suchthat the recirculating shift register memory is read out in a timedsequence compatible with the transmission of FSK modulation to atransmitter. It will be appreciated that parallel-to-serial conversionregister 770 is loaded in synchronism with the clocking of therecirculating shift register memory during the specially timed readout.By virtue of the specially generated clocking signals.Iadd.,.Iaddend.the recirculating shift register is read out in parallel a wordat a time to the parallel-to-serial conversion register. Thereafter, theparallel-to-serial conversion register is clocked serially to read outthis word.

With the output of the parallel-to-serial conversion register 770 beingapplied to a conventional FSK modulator.Iadd., .Iaddend.it will beappreciated in one embodiment that the signal from the FSK modulator maycontain an address code followed by a message. The addresses will, ofcourse, be entered from the keyboard as a prefix to the message to betransmitted. The pager which receives this message obviously does notdisplay the address code.Iadd.; .Iaddend.but.Iadd., .Iaddend..[.is.].rather.Iadd., is .Iaddend.actuated after receipt and decoding of itsparticular address code. Thus, in the case of digital addresses.Iadd.,.Iaddend.the keyboard of the subject pager may be utilized to formulatethese addresses.

In another aspect of the subject invention.Iadd., .Iaddend.it is afeature that the same counter provides a timing sequence to refresh theLED dot matrix display by reading out the memory cyclically and providesfor the encoding of signals .[.(i.e., character codes).]. to be readinto the recirculating shift register memory. In one configuration,illustrated in FIG. 3, an n-bit binary counter 800 in display refreshand encoder timing circuit 746 is utilized which has a certain number ofleast significant bits, for purposes of illustration in this case,.[.4.]. .Iadd.four.Iaddend.. These .Iadd.four .Iaddend.least significantbits are utilized through a .[.1-out of-16.]. .Iadd.one-out-of-sixteen.Iaddend.binary decoder circuit 802 to drive the display made up ofmultiple 5×7 dot matrices 803 via column drivers 804 and to driveencoder keyboard 734 such that the data is read out in three characterblocks. The rows of matrices 803 are driven by row driver 806 inaccordance with dot matrix character generator 742. After the .[.4.]..Iadd.four .Iaddend.least significant bits, the next least significantbits are then routed to a row driver group enable decoder 807.Iadd.,.Iaddend.also in circuit 746.Iadd., .Iaddend.which is utilized to drivethe next group of characters to be presented. In this manner.Iadd.,.Iaddend.the message is grouped via sets of three characters and.Iadd.,.Iaddend.in this sense.Iadd., .Iaddend.the character generation anddisplay is multiplexed. The use of the n-bit binary counter sets themultiplexing for the display such that a minimum of row and columndrivers are required. This counter is used both in the encoding of amessage when the message is to be encoded as well as in the driving ofthe display. What will now be described is the interaction of thekeyboard with the n-bit binary counter to provide the .[.6.]. .Iadd.six.Iaddend.bit ASCII character codes during the encoding operation.

As mentioned before, a .[.one-out-of 1.]. .Iadd.one-out-of-sixteen.Iaddend.binary decoder 802 is provided along with .[.15.]..Iadd.fifteen .Iaddend.column drivers.[.,.]. and .[.16.]. .Iadd.sixteen.Iaddend.column keyboard matrix 734. The function of this binary decoderis to decode the .[.4.]. .Iadd.four .Iaddend.least significant bits ofthe n-bit binary counter and to simultaneously drive both the columndrivers in sets of five and the .[.16.]. .Iadd.sixteen .Iaddend.columnsof the keyboard matrix.

In the generation of the .[.6.]. .Iadd.six .Iaddend.bit ASCII codecharacters, the n-bit counter is continuously cycled via timing logic816 to sequentially present by its states all ASCII character codes to adata register 808. Binary decoder 802 is also cycled to produce outputpulses at its output terminals in a serial fashion so that during acomplete cycle all characters are available as a combination of thesignals from the n-bit counter. At the same time, the cycling binarydecoder outputs are used to drive the columns to the display. Thiscycling occurs very rapidly to prevent flicker of the display. Since theoutputs from the binary decoder are applied to different keys in a timedsequence, depending .Iadd.on .Iaddend.the key switch closed at a giventime in the read out cycle, an enable pulse correlated with thecharacter to be encoded is gated over line 809 to data register 808which is fed in parallel with the output of the n-bit binary counter. Atany given time.Iadd., .Iaddend.the n-bit binary counter has an outputwhich corresponds to a given character. Thus, at a given instant oftime, the state of the n-bit counter corresponds to a character, forinstance.Iadd., .Iaddend.the letter "M.[...].".Iadd.. .Iaddend.If the Mkey is depressed at this time, then the data register is loaded toencode M and this character is entered into the recirculating shiftregister memory.

The gating logic for gating the enable pulse to the data register isillustrated in dotted box 810 and operates in combination with the fifthbit of the n-bit shift register. The fifth bit determines whether it isthe top or bottom row of the keyboard which is actuated. In oneembodiment, the keyboard has two rows and .[.16.]. .Iadd.sixteen.Iaddend.columns. An electronic (digital) switch is provided to enablethe choosing of which row of the keyboard is actuated by controlling thestate of the fifth bit in the n-bit shift register. This electronicswitch includes a shift key 812.

In summary, it is the function of the binary decoder in the displayrefresh and keyboard decoder timing circuit 746 to provide .[.16.]..Iadd.sixteen .Iaddend.output terminals and to produce sequentially aseries of pulses, each at a different output terminal .Iadd.wherein.Iaddend.the time that each pulse is generated .[.corresponding.]..Iadd.corresponds .Iaddend.to a state of the counter as it cyclesthrough its .[.16.]. .Iadd.sixteen .Iaddend.states and.Iadd.,.Iaddend.therefore.Iadd., .Iaddend.a character. This relates the outputterminals to the character represented by the state of the n-bit binarycounter. Thus, if a pulse appears at the.Iadd.".Iaddend.0.Iadd.".Iaddend.output of the binary decoder.Iadd.,.Iaddend.this corresponds to a state of the n-bit binary counter andsome predetermined ASCII character. If a pulse appears on the.Iadd.".Iaddend.1.Iadd." .Iaddend.output of the binary counter.Iadd.,.Iaddend.this will occur at a subsequent period of time and indicatesthat the n-bit binary counter has changed thereby to recognize adifferent ASCII character. The closing of a keyboard switch connects thepulse from an associated output of the binary pointer to a gating systemto provide a dump signal to the data register which changes its ASCIIoutput with each change of the n-bit register. The binary decoder cyclesthrough its .[.16.]. .Iadd.sixteen .Iaddend.states sequentially suchthat the depression of a key will produce a clock pulse to the dataregister which clock pulse arrives at a time corresponding to the givencharacter. Thus, in a given sequence.Iadd., .Iaddend.the delivery of adump pulse to the data register results in the dumping of the particularASCII code to the recirculating shift register memory. What hastherefore been accomplished is that by delivering a dump pulse to thedata register at a particular predetermined time in the sequence, then-bit counter state is read out for that character through the dataregister and into the recirculating shift register memory as theappropriate ASCII code.

It will be appreciated, however, that if the key in the keyboard isdepressed for a long period of time, absent any additional circuitry,the character will be repetitively read into the memory. This isundesirable since the depression of a key once is supposed to result inonly one character being read into the memory. A circuit is thereforeutilized which provides that for a single depression of a keyboard key,only one character is read into the recirculating shift register memory.Basically.Iadd., .Iaddend.this is accomplished by reading a clock 314pulse only once for one key depression no matter how long the key isdepressed. If multiple characters of the same type are to be read in,the key must be depressed a number of times.

Thus, the n-bit binary counter and binary decoder act as a single logicblock or circuit to decode the characters entered at the keyboardwhile.Iadd., .Iaddend.at the same time.Iadd., .Iaddend.supplying timingsignals to the column drivers of the display. In this connection,counter 800 is stepped through states representing all of thealpha/numeric characters. The binary decoder decodes these charactersand produces.Iadd., .Iaddend.sequentially.Iadd., .Iaddend.a series oftiming pulses at its output terminals. These signals sequentiallyactuate the columns of the matrices via drivers 804. Simultaneously, anoutput from a particular output terminal of the decoder defines aparticular state of counter 800 and thus a character. It will beappreciated that counter 800 and decoder 802 are clocked quite rapidlysuch that the columns are actuated in quick succession. When a messageis to be displayed, dot matrix character generator 742 is clocked andthe first group row driver is enabled. Generator 742 produces theappropriate signals for energizing the appropriate dots for the firstcolumn of the character to be displayed. On the next clock pulse,generator 742 produces signals for energizing the appropriate dots forthe next column of this same character, etc. Thus.Iadd., .Iaddend.thecolumns are always being quickly strobed while the rows are actuated insynchronism.

For keyboard encoding purposes.Iadd., .Iaddend.the outputs of decoder802 function not as timing signals, but rather as signals indicative ofthe state of the binary counter. For instance, outputs 0-4 cancorrespond to characters A, B, C, and D. As mentioned before, the fifthn-bit binary counter output can be used to designate whether switches1-16 are activated or switches 17-32. Thus.Iadd., .Iaddend.the .[.16.]..Iadd.sixteen .Iaddend.outputs of the decoder can determine .[.32.]..Iadd.thirty-two .Iaddend.characters. If during the strobing aparticular key is depressed, sometime during the strobing cycle a pulsewill be delivered to logic 810 to cause data shift register 808 totransmit a binary code to the recirculating shift register memory.Because the pulse transmitted corresponds in time to a particular stateof the n-bit counter, the character read out of the n-bit counter atthis time is the one corresponding to the key depressed.

In this way.Iadd., .Iaddend.the same logic circuit serves to generateone set of signals for both display timing and character designation.

It will be noted that both the row drivers and the column drivers aremultiplexed. First.Iadd., .Iaddend.the leftmost group row driver isactivated simultaneously with the sequential activation of the columnsassociated with the three leftmost column drivers. After the first threematrices are activated, the next group row driver is activated and thenext set of three matrices is enabled. Thus.Iadd., .Iaddend.the matricesare enabled in sets of three. In this embodiment.Iadd., .Iaddend.rowdriver selection is accomplished by circuitry within row enable decoder807. It will be appreciated that the column drivers are sequenced by theconnections of the column drivers to successive output terminals ofdecoder 802.

Although a specific .[.emobdiment.]. .Iadd.embodiment .Iaddend.to theinvention has been described in considerable detail for illustrativepurposes, many modifications will occur to those skilled in the art. Itis therefore desired that the protection afforded by Letters Patent belimited only by the true scope of the appended claims.

I claim:
 1. A pager for displaying a message in alpha/numeric formcomprising:means for receiving address signals and coded messagesignals; means for decoding said address .[.-.]. signals and forgenerating an actuation signal; an internal memory for storing receivedmessage signals; means for displaying an alpha/numeric message of apredetermined length.Iadd., .Iaddend.said display .Iadd.means.Iaddend.having character display means at different lateral locations;means responsive to said actuation signal for loading said messagesignals into said memory; and means for reading out said memory,decoding the signals read out from said memory and for driving saiddisplay means with the decoded message in such a manner that saidmessage precesses across said display by lateral displacement of acharacter in the message a number of times to next adjacent characterlocations.[.,.]. so that the character moves across the display from oneside of the display to the other side, whereby long messages for apredetermined recipient may be displayed on a limited length display ina personally portable unit.
 2. The pager of claim 1 wherein said memoryis a recirculating memory which recirculates to precess the message. 3.The pager of claim 2 wherein said recirculating memory includes a shiftregister and means for advancing said shift register.
 4. The pager ofclaim 3 wherein said pager includes means for freezing the precessionand wherein said advancing means selectively advances said shiftregister continuously and a character at a time.
 5. The pager of claim 1wherein said display includes a number of light emitting diodes fordefining the alpha/numeric character.
 6. The pager of claim 5 whereinsaid light emitting diodes are arranged in a dot matrix.
 7. Acombination pager and message encoder comprising:means for decoding a.Iadd.first .Iaddend.message transmitted to said pager; means fordisplaying said decoded .Iadd.first .Iaddend.message in a precessingdisplay in which characters in the .Iadd.decoded first .Iaddend.messageare laterally displaced a number of times to next adjacent characterlocations so that the characters move across the display from one sideto the other side; means including a keyboard for .Iadd.composing and.Iaddend.encoding a .Iadd.second .Iaddend.message; and means forcoupling said .[.encoded.]. .Iadd.second .Iaddend.message to saidprecessing display, whereby a single precessing display is used for bothmessage reception and message .[.encoding.]. .Iadd.composition..Iaddend.
 8. The combination pager and message encoder of claim 7wherein said encoding means further includes means for forming aserially encoded message stream corresponding to said encoded message.9. The combination pager and message encoder of claim 8 and furtherincluding means adapted to couple said message stream to a telephoneline via an acoustic coupler.
 10. The combination of claim 8 and furtherincluding means at said pager and encoder for directly transmitting saidmessage stream to other pagers in the vicinity of said pager-encodercombination.
 11. In a pager adapted to receive .Iadd.encoded.Iaddend.messages transmitted from a remote location,means for decodingthe transmitted message .Iadd.into a form suitable for display;.Iaddend.and means for displaying said decoded message in a precessingdisplay in which characters in said decoded message are laterallydisplaced a number of times to next adjacent character locations so thatthe characters move across the display from one side to the other. 12.For use in combination with common carrier paging transmission apparatushaving .[.a voice.]. .Iadd.an audio .Iaddend.channel.Iadd.,a deviceincluding .Iaddend.an encoder remote from said apparatus having akeyboard for entering a message and means for transmitting to saidpaging transmission apparatus a series of coded audio tones indicative.[.to.]. .Iadd.of .Iaddend.the message entered at said keyboard.Iadd.,said device including a precessing display for displaying portions ofthe message entered at said keyboard in which characters are laterallydisplaced a number of times to next adjacent character locations so thatthe characters move from one side of the display to the other;.Iaddend.and means for coupling said encoder to the audio channel ofsaid transmitting apparatus, whereby the encoded message may betransmitted to a predetermined recipient via said audio channel aftersaid apparatus has transmitted a predetermined address. .[.13. Theencoder of claim 12 and further including a precessing display at saidencoder for displaying portions of the message entered at said keyboardin which characters are laterally displaced a number of times to nextadjacent character locations so that the characters move from one sideof the display to the other..].
 4. The encoder of claim .[.13.]..Iadd.12 .Iaddend.wherein said precessing display includes arecirculating memory for storing the message entered at said keyboard,and means for driving said display in accordance with the output of saidrecirculating memory, said recirculating memory being coupled to saidprecessing display through said drive means for driving it in aprecessing manner with the recirculation of said memory. . A method fortransmitting an alpha/numeric message to a predetermined pager adaptedto receive and display the message .Iadd.and having an address.Iaddend.,comprising the steps of:.Iadd.encoding said message and, simultaneouslyin a precessing alpha/numeric display, precessing said message acrosssaid display such that characters in the message are laterally displaceda number of times to next adjacent character locations so that thecharacters move from one side of the display to the other; .Iaddend.dialing a telephone number corresponding to said .[.predetermined.].address, transmitting signals on an RF carrier.Iadd.,.Iaddend.indicative of said .[.predetermined.]. address to activate saidpredetermined pager from a central transmitter .Iadd.remote from saidencoding and from said display.Iaddend.; .[.and.]. .Iadd.wherein saidencoding step, said dialing step and said first transmitting step beingperformed in any relative order, provided that said dialing stepprecedes said first transmitting step and said second transmitting step;converting the encoded message produced by said encoding step into aseries of audio tones indicative of said message; .Iaddend..[.generating a series of audio tones indicative of.]. .Iadd.couplingsaid audio tones to said transmitter; and transmitting .Iaddend.saidmessage on the carrier from said central transmitter after transmittingsaid address signals.[., said generating step including the steps ofencoding said message at a location remote from said transmitter,converting said encoded message into audio tones, and coupling saidaudio tones to said transmitter.]..
 16. A message encoding unitcomprising:means including a keyboard for encoding a message; a memoryfor storing the encoded message; a display including an arrangement ofdisplay elements, selected elements being .[.actuateable.]..Iadd.actuatable .Iaddend.to present an alpha/numeric character; meansfor driving said display in accordance with selected characters in saidmemory such that a portion of an alpha/numeric message is presented bysaid display at any given time, said drive means including means forprecessing said message across said display such that characters in themessage are laterally displaced a number of times to next adjacentcharacter locations so that the characters move from one side of saiddisplay to the other; and means for decoding the message in said memoryand for making said decoded message available at an output thereof. 17.The message encoding unit of claim 16 wherein said memory includes arecirculating shift register memory and wherein said drive meansincludes means for incrementing said shift register memory.
 18. Themessage encoding unit of claim 17 wherein said means for making saiddecoded message available includes means coupled to said memory forconverting the message therein into a serial bit stream and means forcoupling said serial bit stream to said output. . The message encodingunit of claim 16 wherein said drive means includes means for inhibitingsaid precession.
 20. The message encoding unit of claim 19 wherein saidmemory includes a recirculating shift register memory, wherein saiddrive means includes means for incrementing said shift register memoryand wherein said precession inhibiting means includes means forinhibiting said incrementing means.
 21. The encoding unit of claim 16wherein said display includes a dot matrix arrangement of displayelements.
 22. The encoding unit of claim 16 wherein said displayincludes light emitting diode elements. .Iadd.23. A combination pagerand message encoder comprising:means for decoding a first messagetransmitted to said pager; means for displaying said decoded firstmessage in a precessing display in which characters in the decoded firstmessage are laterally displaced a number of times to next adjacentcharacter locations so that the characters move across the display fromone side to the other; means including a keyboard for composing andencoding a second message; and means for coupling said second message tosaid displaying means, whereby a single precessing display is used forboth message reception and message composition. .Iaddend. .Iadd.24. Theencoder of claim 14 wherein said recirculating memory comprises a memoryof capacity greater than that necessary to contain as many characters ascan be displayed in said display at any one time. .Iaddend. .Iadd.25. Amethod as recited in claim 15, wherein said encoding step comprisesencoding said message in a memory remote from said central transmitter..Iaddend. .Iadd.26. A method for transmitting an alpha/numeric messageto a predetermined pager adapted to receive and display the message,comprising the steps of:dialing a telephone number corresponding to apredetermined address; transmitting signals on an RF carrier indicativeof said predetermined address to activate said predetermined pager froma central transmitter; and generating a series of audio tones indicativeof said message on the carrier from said central transmitter aftertransmitting said address signals, said generating step including thesteps of encoding said message while simultaneously displaying saidmessage in a precessing alpha/numeric display which precesses saidmessage across said display such that characters in the message arelaterally displaced a number of times to next adajcent characterlocations so that the characters move from one side of the display tothe other at a location remote from said transmitter, converting saidencoded message into audio tones, an coupling said audio tones to saidtransmitter. .Iaddend. .Iadd.27. A method as recited in claim 26,wherein said encoding step comprises encoding said message in a memoryat a location remote from said central transmitter. .Iaddend.